This grant supports a broad program of research on regulatory mechanisms of carbohydrate metabolism and their possible derangements in cancer. Current studies are directed toward isozyme alterations in the Morris hepatomas, with particular attention to the pyruvate kinase, glycogen synthetases and phosphorylases, and the carbamyl phosphate synthetases. In addition, studies are under way to determine the rates of synthesis and degradation of phosphoenolpyruvate carboxykinase, aldolase A, and the tumor-associated forms of phosphorylase and pyruvate kinase, using immunologic and radiochemical procedures. Model systems for these experiments are the Morris hepatomas, and various lines of liver and tumor cells cultured in vitro.